Clutch



Bri 4 l1g 13. l940 w. s. WQLFRAM 2,211,191

CLUTCH Filed Aug. 12. 19s? 2 sheets-sheet 1 93 l u M- 1 67 A (ttornegsAug. 13, y1940. w. s. woLFRAM 2,211,191

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' Filed Aug. 12. 19s? z sheets-sheet 2 49 To CLUTCH 57 .77, r M' 27 5f.f/ i Wj? n 2.9 Z5 .53 A. 55

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nventor To PUMP ag w WM' Gttornegs Patented Aug. 13, 1940 NHTED STATESman 'PATENT OFFICE 2,211,191 CLUTCH Application August 12, 1937, SerialNo. 153,630

9 Claims. (fill. 19E-91) This invention relates to releasable frictionclutches such as are used to couple the engine of a motor vehicle withthe change speed transmission.

The novel clutch has for one object the elimination oi the conventionalheavy pedal and linkage and the substitution of light equivalentsoperable with greatly reduced pedal pressure.

The invention has for another object a reduction in the axial length ofthe clutch housing, using with such a housing a cover of light weightmetal. The changes in the operating mechanism maire possible theprovision of means for better y dampening through the use of unusuallylarge cushioning springs. The-novel clutch aims to secure increasedtorque capacity and improved ventilation. -Its construction is such asto avoid the possibility of lubricating medium reaching the plates, andit accomplishes this object, through the elimination of the conventionalthrow-out collar with its provision for lubrication. The novel clutchinsures adequate pressure plate area and a reduction of load on thecrankshaft thrust bearing, the latter resulting from the absence o aclutch throw-out load.

Along with the above objects are reduction in cost of manufacture,greater ease oi operation and reduction in weight. A more specificobject is the accomplishment of the above-mentioned objects by theprovision of a simple hydraulic operating mechanism which is valvecontrolled by the operator and derives its energy from the fluid pumpsupplying the engine bearings with lubricant. y

Other objects and advantages will be understood from the followingdescription In the drawings:

Figure l is a side elevation showing the novel clutch installed in amotor vehicle.

'Figure 2 is a transverse section through the clutch.

Figure 3 is a view in elevation as seen from line 3 3 of Figure 2.

Figure 4 is a section through the control valve. reference being made toune c s of Figure i.

Referring to the several figures of the drawings, numeral 'l is used toidentify the engine of the motor vehicle and 9 and l l are the clutchhousing and change speed housing respectively.

The clutch housing is materially reduced in length from the conventionalclutch housing and of less weight, this change being made possible bythe clutch operating mechanism to be described below. Access to theinterior of the clutch housing is made possible by a light metal coveri3 secured in any convenient way.

Instead of the conventional heavy clutch pedal there is used a lightpedal l5 hinged to the noorboard il' at it, this pedal being normallyheld in 5 released position by a spring 2l. The pedal carries securedthereto a rod 23 having at its end an opening 25 to receive thebent-over end 2l of a stem 29. The stem t@ passes through a plug 35threaded into the end of the valve cylinder 33. l0 Within the cylinder33 is a valve member identified as a Whole by numeral 3l. rIhis valvemember or piston has two heads 3l and 39 between which is a recess lll.At ifi is an inlet opening for' pipe l5 which may communicate in l5 anypreferred way with the discharge side or the conventional oil pump usedfor supplying engine bearings with lubricant.

At il is an opening for a pipe il@ serving the purpose of transmittingoil to the clutch releasing ge mechanism as will be explained below. Thecylinder 35i may be secured to the engine as shown and has otheropenings 5l, 52 and 53 communieating with the crankcase opening 55covered by the cylinder. Openings 5l and 53 serve the 25 purpose ofpreventing any pressure build up between the Valve piston and the endsof the cylinder. A spring 5l is attached to the end 2l of stem 29 and tothe casing t. It serves to bias l the stem and piston to the positionshown in 30 Figure 4 in which the opening 33 for the admission oi fluidpressure from the pump is closed by the head 3l, and in which opening 52communicates with recess il whereby uid from the clutch releasingmechanism may return by way of pipe 35 d@ to the crankcase. To releasethe clutch the pedal is depressed as is customary. In the present casethe depressing effort on the pedal is resisted only by light springs.When so depressed openings cl3 and il are in communication by way 40 ofthe channel @l and the pump pressure is transmitted to the clutchreleasing mechanism.

In Figure 2 are shown the clutch elements and the mechanism by which theclutch is normally held engaged. This gure also shows the ir'd 45pressure parts by which the clutch is released. In this iigure the endof the crankshaft s shown at 57 rotatably supported at 53 in a bearingwhich, in this case, is an integral part; of the housing 9. Fasteningmeans tl secure the flywheel 63 to the 50 crankshaft ange as usual. Theflywheel is equipped with the usual ring" gear t5 for engagement with anengine starting pinion. Reciprocable through the flywheel are aplurality of pins 61. The pins have shoulders 69 and reduced 55 parts1|. On the reduced parts is mounted a more or less conventional pressureplate 1I.'the pressure plate being secured by nuts 15. For coolingpurposes the pressure plate may be provided with air circulating ns 16.Driven shaft 11, the shaft which enters the transmissionhousing i I, ispiloted at 19 in the end oi' the crankshaft and non-rotatably mountedthereon is the hub 8i of the driven clutch disc. The disc proper 85 isyieldingly secured to the hub by cushioning springs 83 of conventionalform but of larger than usual size. To drivingly grip the driven platebetween the ywheel and the pressure plate there is used a spring of theBelleville disc type. This spring is marked by numeral 89. A metallicring 9| is positioned 4by the pins 61. the latter having heads 93engaged by the ring 9|. The Belleville spring 89 engages this ring 9| atits outer periphery. To the flywheel are threaded bolts 95 between theheads of which and the iiywheel surface are rings 91 Aand 99. The spring89 is received between these rings and has openings to receive thebolts. Radially inward from the region of the bolts 95, the springpreferably is provided with slots lili which extend to its inner edge.That part of the spring 89 between the circle of pins 6l and the circleof bolts 96 is unbroken. The spring plate is of bowed form whenunstressed and must be distorted toward the form of a at plate in theprocess of assembly with the pins and bolts. When so assembled it isunder tension and its tension in seeking to return to its unstrainedcondition causes it to press outwardly on ring 9|, ring 99 being itsreaction abutment. In so functioning it reciprocates pins (il toward theleft (Figure 2) and the driven plate is gripped between the flywheel andthe pressure plate.

To overcome the above described clutching action of the spring and torelease the pressure of the pressure plate upon the driven plate, thefollowing construction has been adopted. An annular cup |63 ispositioned within an annular recess of the flywheel. The cup has aradical outer ange H05 held against the flywheel surface by the bolts 95and it has an inner flange |01 held clamped between the adjacent facesof the crankshaft flange and the flywheel by the above describedfastening means 6|. Within the channel of cup H23 is a bellows |09, thebellows being formed by two circular plaited rings lil and H3 of metalsuch as brass or the like, the rings being spaced and secured to thebase of the cup |03. The bellows is completed by an annular ring H5 towhich the plaited rings are secured as by soldering or otherwise. RingH5 has an annular projecting rib li? adapted to contact with the innermargin of the spring disc 89.

For the admission of fluid to the bellows the pipe B9 opens to a radialpassage H9 in the crankshaft bearing as shown in Figure 2, there beingan annular channel |2| in the bearing at the inner end of the radialpassage i i9.

In the end of the crankshaft there is a radial passage |23 at all timescommunicating with channel |2I. From this radial passage |23 a more orless axial passage |25 communicates with an aligned extension passage|21 in the iiywheel and from passage |21 a somewhat radial passage |29communicates with the bellows |09 by way of an opening inthe base of thecup |03.

When the valve is positioned as shown in Figure 4 no fluid from the pumpis permitted to ow through the passage to the bellows, but any fluid inthe bellows may iiow back through the passages indicated into the spacebetween the valve heads" and 3l and out of the cranicsse through openingl2. When the fluid is thus released, the inherent resiliency of spring89 acting against a reaction circle at 99 pushes against the pins l1 andeffects clutch engagement as ex. plained above. When the clutch is to bereleased the pedal lli is depressed. The depression moves the valveparts so that openings Il and 41 are in communication through thechannel Il and outlet l2 is closed. Thereupon the fluid under pressurepasses to the bellows and as it expands ring I Il lifts spring 89 of!its abutment 99 and rocks it about the ring 81. In so doing the outwardpressure on the ring 9| is relieved and the grip of the pressure plateupon the driven plate is released. The outer edge of the spring 89 maythen move the pin 81 to the right (Figure 2) and release the clutch,there being a shoulder at 91 on each pin 81 for engagement with thespring 89 whereby the movement of the pins to the right positively movesthe pressure plate away from the driven plate.

With the above described arrangements, it will be obvious that theobjects of the invention enumerated above are accomplished.

I claim:

1. In a clutch. a first driving member having a frictional face, asecond driving member axially spaced from the first driving member.guiding means whereby the second driving member may move toward and fromthe first driving member. a driven member between and adapted to begripped by said driving members. yieldable mechanism supported on theside of the first driving member remote from the side having thefriction face and from the second driving member, said yieldablemechanism having inherent resiliency and operable to move said seconddriving member toward the first driving member and hydraulic mechanismalso on said remote side of the rst driving member to cause said seconddriving member to move away from the first driving member.

2. The invention defined by claim l, said yieldable mechanism operablethrough the instrumentality of said guiding means.

3. In a clutch, a ywheel having a friction face, a pressure plateaxially movable toward said fiywheel. yieldable mechanism havinginherent resiliency to draw said pressure plate toward said flywheel, adriven member between said flywheel and pressure plate, and annularaxially expansible hydraulic device concentric with said flywheellocated on the side of the flywheel remote from the side having thefriction face and operable by expansion upon said yieldable mechanism topermit said pressure plate to move away from said flywheel.

4. The invention defined by claim 3, said pressure plate being on oneside of said flywheel and said yieldable mechanism being on the sameside of the flywheel as the hydraulic device.

5. In a clutch, a fiywheel, a pressure plate axially movable toward saidflywheel, yieldable mechanism to draw said pressure plate toward saidflywheel, a driven member between said flywheel and pressure plate, anannular axially expansible hydraulic device concentric with saidflywheel and operable by expansion upon said yieldable mechanism topermit said pressure plate to move away from said flywheel, saidflywheel having an annular groove and said hydraulic device comprising ametallic bellows positioned in said groove.

6. In a clutch, a ywheel, a. pressure plate axially movable toward saidflywheel, yieldable mechanism to draw said pressure plate toward saidflywheel, a driven member between said ywheel and pressure plate, anannular axially expansibie hydraulic device concentric with saidflywheel and operable by expansion upon said yieldable mechanism topermit said pressure plate l to move away from said flywheel, togetherwith guiding means for said pressure plate extending through saidflywheel, fulcrum pins carried by said flywheel on the side thereofremote from Asaid pressure plate, said yieldable mechanism consisting ofa Belleville spring preferably engaging said guiding means and anchoredto said ywheel by said fulcrum pins, said ywheel having an annulargroove concentric therewith, said hydraulic device positioned in saidgroove and operable upon the radially inner margin of said yieldingmeans. l

'7. In`a clutch, a :flywheel having a friction face, a pressure plate, adriven member between and engaged by said friction face and pressureplate, yieldable mechanism to move said pressure plate towards saidflywheel into clutch engaging position, hydraulic means having a movablepart directly to engage and move said yieldable mechanism whereby theyieldable mechanism releases said pressure plate from clutch engagingposition, l

said pressure plate being located on one side of said flywheel and saidyieldable mechanism and hydraulic means being located on the side of theflywheel remote from said friction face.

8. In a clutch, a flywheel, a pressure plate, a

driven member therebetween, yieldable mechanism to move said pressureplate towards said flywheel into clutch engaging position, hydraulicmeans having a movable part to engage and move said yieldable mechanismwhereby the yieldable mechanism releases saidl pressure plate fromclutch engaging position, said pressure plate being on one side of theywheel, guide pins secured to said pressure plate and extending throughthe ywheel, said yieldable mechanism being on the other side of saidflywheel, anchored thereto and engaging said pins, said hydraulic meansalso being upon said other side of the ywheel and operable upon saidyieldable mechanism to stress the same and relieve the pressure platefrom the influence of the yieldable mechanism.

9. The invention dened by claim 7, said yieldable mechanism alsooperable in response to said hydraulicmeans to positively move saidpressure plate to clutch releasing position.

wILuAM s. woLmAM.

